NMR is used for the non-invasive study of aging in animals and cells, and for the study of age changes in human arms and legs. A biospec spectrometer (300/1.9) is used to study age changes in animals by multinuclear spectroscopy, using 2-dimensional NMR and saturation transfer techniques to study how metabolic rates of exchange change with age. The metabolic changes are compared to morphological changes studied by imaging techniques, which are also useful for studying changes in the distribution of drugs and metabolites. Probes designed for use with a narrow-bore Varian XL-200 spectrometer are employed to perfuse cells such as human fibroblasts of varying passage and from donors of different ages. Metabolism of the cells is studied by multinuclear NMR techniques.